State Water Resources Research Institute Program (WRRI)
USGS Grant Number: G12AP20153
Start Date: 2012-09-01 End Date: 2014-08-31
Total Federal Funds: $102,681 Total Non-Federal Funds: $102,686
Principal Investigators: William Arnold
Abstract: Prairie pothole lakes (PPLs) are an important hydrological feature in central North America. Many have been drained, changing them into transient features with artifical connections to surface and groundwaters. In some cases, PPLs are also being restored as constructed wetlands. Because the prairie pothole lakes are also located within an extensively farmed region of the United States, they are susceptible to pesticide contamination via non-point source pollution. The interconnectedness of water resources in the prairie pothole region makes the problem of non-point source pollution particularly difficult. A holistic approach to water management that not only considers flows, but also considers chemical and biological processes is necessary to create a sustainable management plan. The proposal seeks to provide necessary information for such a plan. Specifically, we will determine the importance of pesticide attenuation via photolysis in PPLs, the relative importance of indirect photolysis, and we will evaluate how differences in PPL lifetime/drainage scenarios affect pesticide attenuation. Results from this research will 1) verify the potential of PPLs for the natural attenuation of pesticides via photolysis, 2) evaluate how this potential compares between drained, restored, and native PPLs, and 3) provide guidance to maximize pesticide removal in PPLs based on retention time, water depth, light attenuation, PPRI levels, and direct photolysis rates. This work will lead to alteration of drainage strategies to optimize pesticide degradation and crop protection via the control of drainage rates and aid in the proper design of reconstructed wetlands, which are applicable to agricultural regions across the country.